/** * Copyright (C) 2009 - 2012 SC 4ViewSoft SRL * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.achartengine; import org.achartengine.chart.AbstractChart; import org.achartengine.chart.RoundChart; import org.achartengine.chart.XYChart; import org.achartengine.renderer.DefaultRenderer; import org.achartengine.tools.Pan; import org.achartengine.tools.PanListener; import org.achartengine.tools.Zoom; import org.achartengine.tools.ZoomListener; import android.graphics.RectF; import android.view.MotionEvent; /** * The main handler of the touch events. */ public class TouchHandler implements ITouchHandler { /** The chart renderer. */ private DefaultRenderer mRenderer; /** The old x coordinate. */ private float oldX; /** The old y coordinate. */ private float oldY; /** The old x2 coordinate. */ private float oldX2; /** The old y2 coordinate. */ private float oldY2; /** The zoom buttons rectangle. */ private RectF zoomR = new RectF(); /** The pan tool. */ private Pan mPan; /** The zoom for the pinch gesture. */ private Zoom mPinchZoom; /** The graphical view. */ private GraphicalView graphicalView; /** * Creates a new graphical view. * * @param view the graphical view * @param chart the chart to be drawn */ public TouchHandler(GraphicalView view, AbstractChart chart) { graphicalView = view; zoomR = graphicalView.getZoomRectangle(); if (chart instanceof XYChart) { mRenderer = ((XYChart) chart).getRenderer(); } else { mRenderer = ((RoundChart) chart).getRenderer(); } if (mRenderer.isPanEnabled()) { mPan = new Pan(chart); } if (mRenderer.isZoomEnabled()) { mPinchZoom = new Zoom(chart, true, 1); } } /** * Handles the touch event. * * @param event the touch event */ public boolean handleTouch(MotionEvent event) { int action = event.getAction(); if (mRenderer != null && action == MotionEvent.ACTION_MOVE) { if (oldX >= 0 || oldY >= 0) { float newX = event.getX(0); float newY = event.getY(0); if (event.getPointerCount() > 1 && (oldX2 >= 0 || oldY2 >= 0) && mRenderer.isZoomEnabled()) { float newX2 = event.getX(1); float newY2 = event.getY(1); float newDeltaX = Math.abs(newX - newX2); float newDeltaY = Math.abs(newY - newY2); float oldDeltaX = Math.abs(oldX - oldX2); float oldDeltaY = Math.abs(oldY - oldY2); float zoomRate = 1; float tan1 = Math.abs(newY - oldY) / Math.abs(newX - oldX); float tan2 = Math.abs(newY2 - oldY2) / Math.abs(newX2 - oldX2); if ( tan1 <= 0.577 && tan2 <= 0.577) { // horizontal pinch zoom, |deltaY| / |deltaX| is [0 ~ 0.577], 0.577 is the approximate value of tan(Pi/6) zoomRate = newDeltaX / oldDeltaX; if (zoomRate > 0.909 && zoomRate < 1.1) { mPinchZoom.setZoomRate(zoomRate); mPinchZoom.apply(Zoom.ZOOM_AXIS_X); } } else if ( tan1 >= 1.732 && tan2 >= 1.732 ) { // pinch zoom vertically, |deltaY| / |deltaX| is [1.732 ~ infinity], 1.732 is the approximate value of tan(Pi/3) zoomRate = newDeltaY / oldDeltaY; if (zoomRate > 0.909 && zoomRate < 1.1) { mPinchZoom.setZoomRate(zoomRate); mPinchZoom.apply(Zoom.ZOOM_AXIS_Y); } } else if ( (tan1 > 0.577 && tan1 < 1.732) && (tan2 > 0.577 && tan2 < 1.732) ){ // pinch zoom diagonally if (Math.abs(newX - oldX) >= Math.abs(newY - oldY)) { zoomRate = newDeltaX / oldDeltaX; } else { zoomRate = newDeltaY / oldDeltaY; } if (zoomRate > 0.909 && zoomRate < 1.1) { mPinchZoom.setZoomRate(zoomRate); mPinchZoom.apply(Zoom.ZOOM_AXIS_XY); } } oldX2 = newX2; oldY2 = newY2; } else if (mRenderer.isPanEnabled()) { mPan.apply(oldX, oldY, newX, newY); oldX2 = 0; oldY2 = 0; } oldX = newX; oldY = newY; graphicalView.repaint(); return true; } } else if (action == MotionEvent.ACTION_DOWN) { oldX = event.getX(0); oldY = event.getY(0); if (mRenderer != null && mRenderer.isZoomEnabled() && zoomR.contains(oldX, oldY)) { if (oldX < zoomR.left + zoomR.width() / 3) { graphicalView.zoomIn(); } else if (oldX < zoomR.left + zoomR.width() * 2 / 3) { graphicalView.zoomOut(); } else { graphicalView.zoomReset(); } return true; } } else if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_POINTER_UP) { oldX = 0; oldY = 0; oldX2 = 0; oldY2 = 0; if (action == MotionEvent.ACTION_POINTER_UP) { oldX = -1; oldY = -1; } } return !mRenderer.isClickEnabled(); } /** * Adds a new zoom listener. * * @param listener zoom listener */ public void addZoomListener(ZoomListener listener) { if (mPinchZoom != null) { mPinchZoom.addZoomListener(listener); } } /** * Removes a zoom listener. * * @param listener zoom listener */ public void removeZoomListener(ZoomListener listener) { if (mPinchZoom != null) { mPinchZoom.removeZoomListener(listener); } } /** * Adds a new pan listener. * * @param listener pan listener */ public void addPanListener(PanListener listener) { if (mPan != null) { mPan.addPanListener(listener); } } /** * Removes a pan listener. * * @param listener pan listener */ public void removePanListener(PanListener listener) { if (mPan != null) { mPan.removePanListener(listener); } } }